EP2512935A1

EP2512935A1 - Container having deformable flanks

Info

Publication number: EP2512935A1
Application number: EP10808904A
Authority: EP
Inventors: Michel Boukobza
Original assignee: Sidel Participations SAS
Current assignee: Sidel Participations SAS
Priority date: 2009-12-17
Filing date: 2010-12-16
Publication date: 2012-10-24
Anticipated expiration: 2030-12-16
Also published as: CN102741127B; EP2512935B1; JP2013514239A; CN102741127A; FR2954287B1; WO2011080418A1; US9302840B2; US20130008913A1; MX2012007093A; MX344561B; BR112012014919A2; FR2954287A1

Abstract

The invention relates to a thermoplastic container (1) including a body (2) in which at least one flank (9) is formed by indentation, including: a central area (12) having a concave profile in a longitudinal plane, and an adjacent area (13) longitudinally extending the central area (12) and having a convex profile in a longitudinal plane. The central area (12) and the adjacent area (13) are stiffened, and the junction between the central area (12) and the adjacent area (13) defines a deformable membrane (16).

Description

CONTAINER WITH DEFORMABLE FLANKS

The invention relates to the field of containers, and more particularly thermoplastic containers, for example polyethylene terephthalate (PET), the wall is subjected to stress.

A container is generally manufactured by blow molding or stretch blow molding of an injected preform, which is first heated on the run in a furnace equipped with radiant heating elements, then introduced hot into a mold provided with a cavity defining the counterweight. -print of the container.

The cost of the raw material used in the manufacture of a container largely accounts for the final cost of the container. It therefore seems desirable, in a global policy of cost reduction, to reduce as much as possible the quantity of material used.

This reduction, however, has an impact on the mechanical performances, and the only lightening of the containers can lead to an insufficient rigidity, in particular during the hot filling, during which the wall of a container is subjected to internal stresses because of the thermal shock and hydrostatic pressure variations.

As an indication, the temperature of the liquid during a hot filling frequently exceeds 60 ° C, and commonly reaches 90 ° C to 95 ° C (ie a temperature above the glass transition temperature of PET, a frequently used material).

The container is then cooled, inducing a pressure drop in the container (essentially due to the shrinkage of the volume of air it contains), the walls then being subjected to new constraints opposite to the previous ones.

Also the containers for hot filling (called HR, acronym for the expression "heat resistant") benefit from a suitable manufacturing and special structural provisions making them less sensitive to deformations and allowing them to maintain their shape for a long time. General. In manufacture, a notorious contribution to the rigidity of the container is provided by the heat-setting, which consists, at the end of the blowing operation, in temporarily holding the container in contact with the heated wall of the mold, so as to increase the rate of crystallinity of matter.

However, experience shows that heat-setting alone is not generally sufficient to make a container resistant to the deformations induced by hot filling, and that it is furthermore necessary to provide structural adaptations.

Thus, it is known to provide the container with zones of preferential deformation.

These zones may be provided on the bottom of the container, as in the examples given in the documents WO 2004/02891 0 and US 2006/00061 33. The bottom of the container has a concave or convex shape, so that the bottom is lowered. during hot filling, then rises when cooling.

In theory, the deformations are thus located on the bottom of the container, and the side walls spared do not require any particular shape. In practice, however, it is rare that the side walls are not deformed, so that it appears necessary to provide zones of preferential deformation.

These zones are generally in the form of panels surrounded by rigid frames, which panels, in the manner of membranes, deform by bouncing during filling, and conversely retract when cooling the container. Examples of such panels are given in international applications WO 99/21770 and WO 00/68095.

Containers of this type can be satisfactory from the point of view of performance, but the presence of such panels, surrounded by their rigid frames, has at least two drawbacks: on the one hand, it is a brake on reducing the amount of material ; on the other hand, it restricts designers' creative freedom, HR containers often have, in fact, forms that can be described as austere. A first objective of the invention is to allow additional lightening containers, especially of the type HR, without sacrificing their mechanical performance.

A second object of the invention is to allow the aesthetic improvement of containers with special structural provisions such as zones of preferred deformation (or on the contrary of stiffening).

A third object of the invention is to provide a container with improved ergonomics, facilitating its handling by a consumer.

For this purpose, the invention proposes a container made of thermoplastic material comprising a body in which is hollowed out at least one sidewall comprising:

a central zone having, in a longitudinal plane, a concave profile, and

an auxiliary zone longitudinally extending the central zone and presenting, in a longitudinal plane, a convex profile.

The central zone and the annex zone are stiffened, and a deformable membrane is defined at the junction between the central zone and the annex zone.

The main function of this deformable membrane is to concentrate most of the deformations during a hot filling. This results in a minimization of deformations on the other parts of the container.

The sidewall is preferably designed so that, in the absence of stress, the deformable membrane is substantially flat in a transverse plane.

According to one embodiment, the auxiliary zone presents in a transverse plane a convex profile.

In addition, the flank is preferably delimited by sharp edges.

In addition, the auxiliary zone can be stiffened by means of longitudinal grooves framing the auxiliary zone. Each groove is in this case connected to an intermediate face of the body by a leave whose radius is preferably less than that of another leave connecting the groove to the annex area. The central zone, which is preferably of greater width than that of the adjoining zone, can be stiffened by means of longitudinal ribs protruding from the central zone.

According to one embodiment, the body comprises a plurality of flanks separated by intermediate faces provided with stiffeners.

The sidewall comprises for example a central zone extended longitudinally by two additional zones which may be symmetrical, and whose junctions with the central zone respectively define two deformable membranes.

Other objects and advantages of the invention will become apparent in the light of the description given hereinafter with reference to the appended drawings in which:

Figure 1 is a perspective view of a container comprising three deformable flanks according to a first embodiment; - Figure 2 is a side view of the container of Figure 1, facing a sidewall;

Figure 3 is a side view of the container of Figure 1, along the profile of a sidewall;

Figure 4 is a three quarter view of the container of Figure 1; - Figure 5 is a sectional view of the container of Figure 2 along the line V-V;

Figure 6 is a sectional view of the container of Figure 2 along the line VI-VI;

Figure 7 is a sectional view of the container of Figure 2 along line VI I -VI I;

Figure 8 is a sectional view of the container of Figure 2 along the line VI I-VI I I;

Figure 9 is a detail view of Figure 7 on the profile of a sidewall;

FIG. 10 is a detail view of FIG. 8 on the profile of a sidewall;

Figure 1 1 is a perspective view of a container comprising three deformable flanks according to a second embodiment; Figure 1 2 is a side view of the container of Figure 1 1, facing a sidewall; Figure 13 is a side view of the container of Figure 1 1, along the profile of a sidewall;

Figure 14 is a three quarter view of the container of Figure 1 1; Figure 1 5 is a sectional view of the container of Figure 1 2 along a line XV-XV;

Figure 16 is a sectional view of the container of Figure 1 2 along a line XVI-XVI;

Figure 17 is a sectional view of the container of Figure 1 2 along a line XVI-XVI;

- Figure 18 is a detail view of Figure 1 6 on the profile of a sidewall.

With reference to the figures, there is illustrated a container 1 comprising a central body 2 extending along a main axis 3.

The central body 2 is surmounted by a shoulder 4 of generally conical shape, narrowing to lead to a neck 5 provided with a rim 6 and, in the example, a flange 7 adapted to allow the suspension of the container 1 , especially during filling. The body 2 is closed, opposite the neck 5, by a bottom 8.

For purposes of simplification and clarity, the terms high, low, lower and upper, are taken here with reference to the natural orientation of the containers, it being understood that in the normal position of rest the container 1 is placed on the bottom 8 , the drinking 6 directed upwards, and the main axis 3 of the container 1 oriented vertically. A direction is said longitudinal if it extends parallel to the axis 3 of the container 1; a plane is said to be longitudinal if it contains the axis 3; a plane is said transversal if it is perpendicular to the axis 3.

The container 1 is made of thermoplastic material, for example PET, and can be obtained in a known manner by stretching a pre-heated blank.

The body 2 is hollowed out with a series of depressions flanks 9, which extend between a lower groove on the bottom side 8 and an upper groove 11 on the shoulder side 4.

Each sidewall 9 comprises a concave central zone 12 and at least one convex zone 13 adjoining longitudinally the central zone 12, so that the sidewall 9 has, seen from the side, a corrugated profile. Concavity and conversely convexity are here defined by concave container 1, meaning that the radius of curvature is measured outside the container 1, convex on the contrary that the radius of curvature is measured inwardly.

Two versions of the container 1 are shown in the figures: a first version in FIGS. 1 to 10; a second in Figures 1 1 to 1 7.

In the first version, the container 1 comprises three sidewalls 9 distributed at 120 °, each comprising a concave central zone 12 and a single convex zone annex 13, located on the side of the bottom 8. The sidewalls 9 are separated by intermediate faces 14 to cross-section in a circular arc, and of a general shape complementary to those of the flanks 9.

The width - that is to say, the transverse dimension - of the central zone 12 is greater than that of the annex zone 13. As is clearly visible in FIG. 3, the sidewall 9 has its widest width at the level of the maximum depression of the central zone 12.

The curvature of the central zone 1 2 varies longitudinally: it is substantially constant in the center of the central zone 12, and gradually decreases in the vicinity of the annex zone 13.

Thus, by analogy with the human anatomy, the flank 9 has a longitudinal profile similar to that of a spine, the central zone 12 can be likened to the lumbar portion of the column and the area 13 annex to the sacrum.

As illustrated in the cross sections of Figures 5 to 8, the curvature of the sidewall 9 is also transversely variable. Thus, at the top of the central zone 12, it appears slightly concave in a transverse plane (FIG. 5). In a median plane, at the level of the greatest width, the central zone 12 is, on the contrary, slightly convex (FIG. 6). At the junction between the central zone 12 and the annex zone 13, the sidewall 9 is substantially flat (FIG. 7). Finally, in the annex area 13, the sidewall 9 is convex (FIG. 8).

In other words, the area 13 annex is doubly convex, both in a longitudinal plane in a transverse plane. Thus, the sidewall 9 generally has a shape of spatula or spoon rounded contour, the central area 12 forming the spoon, the zone 1 3 annex forming a portion of the handle.

As can be seen in the drawings, and in particular in the cross section of FIG. 5, at the level of the central zone 12, the contour of each sidewall 9 is delimited by a simple sharp edge 15 (preferably said low radius), connecting the sidewall 9 to the intermediate faces 14 - in contrast to conventional structures with panels delimited by beam type stiffening elements.

At the junction between the central zone 12 and the annex zone 13, the sidewall 9 locally defines a deformable membrane 16, which is substantially flat in the absence of stress, but which can adopt a curvature according to the conditions of temperature and hydrostatic pressure. in the container.

Thus, during a hot filling, the membrane 16 is deformed by bending towards the outside of the container 1, adopting a convex configuration both in a longitudinal plane and in a transverse plane as is shown in solid lines in the figure 9, thus extending the zone 13 annex of the sidewall 9.

Conversely, when the liquid contained in the container 1 - after the latter has been plugged - cools, the retraction of the volume of air that it contains and possibly the retraction of the liquid cause a depression which induces a reversal of the membrane 1 6 deformable, which then adopts a concave configuration both in the longitudinal plane and in the transverse plane as shown in phantom in Figure 9, thus extending the central zone 12 of the sidewall 9.

When the container 1 is then opened by a consumer, the equalization of the pressures again causes the overturning of the membrane 16, which adopts a convex configuration again.

Several arrangements make it possible to better locate the deformations on the membrane 16.

On the one hand, each sidewall 9 is provided with a stiffener 17 which protrudes radially from the bottom of the central zone 12. The stiffener 17 extends longitudinally on either side of a longitudinal center line of the central zone 1 2 and comprises three adjacent ribs 18, 19, namely a central rib 18 and two ribs 19 side adjoining the rib 18 central on both sides thereof. The central rib 18 is of greater height and width than those of the lateral ribs 19. As can be seen in FIG. 6, the central rib 18 has a slightly concave external face 20 whose camber is, however, less than that of the central zone 12 of the sidewall 9.

The central rib 18 extends upwardly to an upper end 21 spaced apart from an upper edge 22 of the central zone, and downwardly to a lower end 23 which abuts the junction between the central zone 12 and the area 13 annex, that is to say the membrane 16 deformable, so that the outer face 20 of the central rib 18 is flush with the outer surface 24 of the membrane 16 deformable.

The stiffener 17 has a dual function. First, during a hot filling, it limits, by its resistance to radial bending, the deformations of the central zone 12 which would tend to bulge under the effect of the temperature and the hydrostatic pressure of the liquid . Then, by its resistance to axial compression, it limits the crushing of the body 2 during stacking of the container 1.

On the other hand, each flank 9 is provided locally, on either side of the zone 1 3 annex, longitudinal grooves 25 V profile with rounded bottom. The grooves 25 are connected laterally to the zone 13 annex by a fillet 26 with a large radius and the adjacent intermediate face 14 by a leave 27 of comparatively smaller radius, the leave 27 of smaller radius thus forming a sharp edge (FIG. ).

The grooves 25 have the function, during hot filling, to limit the deformations of the annex zone 13, the curvature of which would tend to be accentuated by the effect of the temperature and the hydrostatic pressure of the liquid.

It follows from these provisions that, the stiffener 17 limiting the deformations of the central zone 12 and the grooves 25 those of the zone 13 annex, the deformations of the sidewall 9, during a hot filling, are concentrated locally on the non stiffened, namely the deformable membrane 16 which forms the junction between the central zone 12 and the annex area 13. As can be seen in FIGS. 1 to 5, reinforcing means, here longitudinal ribs 28, are also provided projecting on the intermediate faces 14, these ribs 28 having the effect of liming the deformations of the body 2 during an axial compression consecutive to a stack of the container and / or to channel the deformation of the wall of the container causing, at a plane containing these ribs 28, a deformation of said substantially circumscribed wall in a triangle due to the presence of three ribs (one on each intermediate face 14).

It can be seen in Figure 4 that each rib 28 is bent, and has at its ends 29, 30 a width greater than the width at its center 31: it results in a better distribution of stresses along the intermediate face 14.

According to the illustrations, the central zone 12 is here directed towards the rim 6 of the container 1, the zone 13 annex being directed towards the bottom 8. However, this arrangement can be reversed without modifying the functions of the sidewall 9 and its impact on the behavior of the container 1.

In the second version, the container 1 comprises five flanks 9 distributed at 72 °, each comprising a central zone 12 and two zones 13 attached to either side longitudinally of the central zone 12. As in the first version, the width of the central zone 12 is greater than that of the zones 1 3 annexes, the place of greater width corresponding to the maximum depression of the central zone 12.

The flank 9 has a symmetry with respect to a transverse axis passing through the maximum depression of the central zone. Advantageously, the axis of symmetry is placed substantially at half height of the central body 2.

Between two successive flanks 9 is disposed an intermediate face 14 whose transverse profile has a general shape complementary to those of the flanks, in an arc.

The curvature of the central zone 12 varies longitudinally: it has a maximum at the level of the maximum depression, on the axis of symmetry, and gradually decreases in the vicinity of the zones 1 3 annexes.

As illustrated in the cross-sectional views of FIGS. 15 to 17, the curvature of the flanks 9 also varies transversely. In indeed, the curvature on the annexed zones 13 is convex (FIG. 15), this convexity being accentuated as one moves away from the central zone 12. As one approaches the central zone 12, the curvature decreases (FIG. 6) to the middle of the sidewall 9 where it is substantially zero: the sidewall 9 is then substantially flat (FIG. 7). More specifically, near the central zone 1 2, the curvature varies to be reversed substantially in the middle of the sidewall 9: the transverse profile then has a slight undulation (f ig .18), a concave corrugation 32 in the middle being framed by on both sides by two convex waves 33.

In the same way as in the first version, each zone 13 annex is doubly convex, both in a longitudinal plane in a transverse plane.

In the same way as in the first version, the central zone 12 of the flanks 9 is connected to the intermediate faces 14 by a sharp edge 15, that is to say of radius of curvature substantially small compared to that of the intermediate faces.

Thus, the sidewall 9 comprises two deformable membranes 16, at the junction between the central zone 12 and each zone 13 annexed. In the absence of constraints, these deformable zones 16 are preferably substantially flat, but may have a slight curvature, both concave and convex. Under the effect of stresses, depending on the conditions of temperature and hydrostatic pressure, the curvature of these membranes 16 varies to absorb said stresses.

The membranes 1 6 operate in substantially the same manner as in the first version: during a hot filling, the membranes 16 extend the zones 13 annexes, then when the container filled and clogged cools, the membranes 16 extend the zone 1 2 central flank 9.

When the container 1 is then opened by a consumer, the equalization of the pressures again causes the overturning of the membranes 16, which again adopt a convex configuration.

Provisions similar to those already described for the first version are applied in this second version also, in order to better locate the deformations on the membranes 16. Thus, a stiffener 17 is also projecting on the central zone 12 of the sidewalls 9. The stiffener 1 7 extends longitudinally on either side of the longitudinal center line of the sidewall 9. According to the preferred embodiment, which is that illustrated in Figures 1 1 to 1 8, each stiffener 17 has two ribs 18, 19 identical contiguous to form a profile in W. The ribs 1 8 also have a slightly concave outer face, the camber is however less than that of the central zone 12 of the sidewall 9.

The ribs 1 8, 19 extend longitudinally between the two deformable membranes 16 of the flanks 9, the outer faces ending in a bevel and flush with the outer surface of the membranes 16.

Therefore, as for the first version, the stiffener 17 reinforces the resistance of the container 1 to radial bending and radial compression.

The zones 1 3 annexes are framed by longitudinal grooves V-shaped profile with rounded bottom. The grooves 25 are connected to the intermediate face 14 adjacent to the side by a fillet 27 of radius comparatively lower than that of the fillet 26 connecting the grooves 25 to the zone 13 annex.

The flanks 9, reinforced on the central zone 12 and on the annexed zones 13, preferentially undergo deformations at the junction between the central zone 12 and the adjoining zones 13, namely the deformable zones 16.

The intermediate faces 14 also include means for reinforcing them. Thus, ribs 28 and longitudinal notches 34 are placed between the sidewalls 9. As in the previous embodiment, these ribs 28 have the effect of limiting the deformations of the body 2 during axial compression consecutive to a stack of the container. 1 and / or to channel the deformation of the wall of the container 1. For this purpose, they cause, at a plane containing these ribs 28, a deformation of said substantially circumscribed wall in a pentagon due to the presence of five ribs 28 (one on each intermediate face 14).

The ribs 28 of reinforcement are projecting on the intermediate faces 14. The upper end and the lower end of each rib 28 ends in bevel to melt in the intermediate face 14, so that the height of the rib 28 on the intermediate face 14 is maximum next to the central zone 12 and is minimal next to the zones 13 annexes.

The notches 34 are two in number on each intermediate face 14 and are placed in the extension and at a distance from the upper and lower ends 29, 30 of each rib 28 of reinforcement. They are oval in general shape, extending angularly on the intermediate face 14.

From the second version which has just been described, it is possible to produce a flank 9 comprising three or more deformable membranes 16, simply by alternating along the longitudinal direction zone 1 2 central and zone 13 annex.

According to a non-illustrated variant, the sidewall 9 comprises a central zone 12 from which three or more annexed zones 13 start in a star shape, forming three or more deformable membranes 16.

Advantageously, the outer surface of the flanks 9 is provided with cavities 36 limiting the sliding of the container 1 when it is grasped by a user.

The embodiments described through the two versions are not limiting, variants can be made.

Thus, the container 1 may alternatively have flanks comprising a deformable membrane as in the first version with flanks having two or more deformable membranes, as in the second version.

In addition, although in the two versions described here the longitudinal direction is parallel to the main axis 3 of the body 2, the sidewalls 9 may be inclined relative to this axis 3 by an angle of up to 90 °, so that the flanks 9 extend transversely on the body 2 of the container 1.

On either side of the central body 2, the container 1 may be provided with additional stiffening means, such as beads preventing radial deformations. The bottom 8 may also have a stiffened structure. The location of the deformations membranes 1 6 deformable allows to overcome conventional panels while ensuring the preservation of the general shape of the container 1 along the production line.

The number of deformable membranes 16 can be adjusted as needed. Thus, by increasing the number of deformable membranes 16, it is possible to subject the container stresses even higher, or to reduce the amplitude of the deformations undergone by each membrane. It is the same for the number of sidewalls 9, intermediate faces 14, ribs 28 and notches 34. The ribs 28 cause, at a plane containing these ribs 28, a deformation of the wall of the body 2 substantially circumscribed in a polygon whose number of sides is determined by the number of ribs 28.

The flanks 9 formed on the body 2 are distinguished from conventional panels in particular by the fact that they are not delimited by additional structures, such as beams, allowing both to gain material - and therefore weight - and allow aesthetics hitherto unobtainable, while improving the ergonomics of the container with a grip safer and more enjoyable.

Tests carried out on samples of containers 1 with a capacity of 0.51 showed mechanical performances equivalent to those of the known containers for a weight of about 15% (less than 20 g).

Claims

1. Container (1) made of thermoplastic material comprising a body (2) in which at least one side (9) is hollowed out, characterized in that the sidewall (9) comprises:

- a central zone (12) stiffened having, in a longitudinal plane, a concave profile, and

- a zone (13) stiffened annex longitudinally extending the central zone (12) and having, in a longitudinal plane, a convex profile,

- A deformable membrane (16) defined at the junction between the zones (12, 13) stiffened.

2. Container (1) according to claim 1, characterized in that, in the absence of stress, the deformable membrane (16) is substantially flat in a transverse plane.

3. Container (1) according to claim 1 or 2, wherein the zone (13) annex presents in a transverse plane a convex profile.

4. Container (1) according to one of claims 1 to 3, wherein the sidewall (9) is delimited by sharp edges (15, 27).

5. Container (1) according to one of claims 1 to 4, wherein the zone (13) annex is stiffened by means of longitudinal grooves (25) flanking the area (13) annex.

6. Container (1) according to claim 5, wherein each groove (25) is connected to an intermediate face (14) of the body (2) by a fillet (27) whose radius is less than that of a fillet ( 26) connecting the groove (25) to the annex area (13).

7. Container (1) according to one of claims 1 to 6, wherein the zone (12) central is stiffened by means of a stiffener (1 7) extending longitudinally projecting on the zone (12) central.

8. Container (1) according to one of claims 1 to 7, wherein the zone (12) central is wider than the zone (13) annex.

9. Container (1) according to one of claims 1 to 8, wherein the body (2) comprises a plurality of flanks (9) separated by faces (14) intermediate provided with reinforcing means (28, 34).

1 0. Container (1) according to one of claims 1 to 9, wherein the sidewall (9) comprises a zone (12) central longitudinally extended by two zones (13) annexes, whose junctions with the zone (12) central respectively define two membranes (16) deformable.